الفهرس 
Introducation and Aim of the workOnly 14 pages are availabe for public view
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Abstract
There are many modalities for imaging the thorax and its lesions. Since the
discovery of X-ray by Roentgen (1895) and up till now, plain radiography has
remained as the most commonly used imaging modality. However, plain radiography
alone is not enough for the diagnosis of a complex lung disease, due to
the superimposition of multiple structures over each other. For example [e.g.]. a
tumour hidden in massive pleural effusion can not be seen. Moreover, it does
not sometimes give enough data to know the nature of the opacification, since
the density resolution is low (Hoffman et at., 1992).
Computed tomographic [CT] scanning has the capability of demonstrating
well the topographic relationship between different anatomic structures in a
complex lung disease and can declare the nature of the lesions (Yu et at., 1993).
Unfortunately, CT has the disadvantages of high cost and exposure to ionizing
radiation. It also lacks the bedside availability and needs considerable patient
cooperation. Intravenous [IV] injection of a contrast material, with its possible
complications, is essential to visualize the vascular structures and vascular
lesions, and to differentiate them from other structure